Grounding problem at lastnights gig

[JustDavid]

<snip> a Residual Current Breaker, or RCB, that trips if a voltage between live and earth is detected. <snip>

Current, not voltage.

 

[konodl18]

At the risk of repeating what others have said, (but hopefully more succinctly):

All equipment shall have three-wire AC cords, and the ground pin shall be intact. (If I find one in my venue w/o a ground pin, we gonna have a talk.)

All extension cords and power strips shall be three wire and shall have the ground pin intact. (If I find one in my venue w/o a ground pin, I immediately unplug it and cut the connector off so that it cannot be used.)

All equipment shall have the "death cap" removed and the ground switch disconnected.

If the "back of the hand" test still gives you a zap, plug your amp into the same AC outlet that the PA is plugged into.

If you still get a zap, either your amp, the PA, or the venue wiring has a problem.

I may be incorrect but from what I've read this issue normally arises when the PA and the guitar or bass rig are plugged into separate circuits. I think it is a difference in the "ground potential" of the circuits in the building. Correct me if I am wrong or if I phrased it incorrectly.

But yeah, it seems funny sometimes... But sometimes it kills people.

 

[TimmyP]

I may be incorrect but from what I've read this issue normally arises when the PA and the guitar or bass rig are plugged into separate circuits. I think it is a difference in the "ground potential" of the circuits in the building. Correct me if I am wrong or if I phrased it incorrectly.

But yeah, it seems funny sometimes... But sometimes it kills people.

You are correct. BUT: If the amp is not grounded, and especially if it still has the "death cap", there can be quite a lot of voltage on the chassis. Connect a musician between this chassis and a grounded mic, and you have a lot of pain - or worse. This is much more dangerous than the difference between a grounded chassis and a grounded mic.

 

[warnergt]

Are [Ground Fault Circuit Interrupters] in common usage in the U.S.? - I mean do you guys put one between the extension cable and the wall socket as a matter of course?.

When found in the U.S., GFCI is typically built into the outlet. To comply
with the U.S. National Electrical Code since the 1970's, GFCI protection is
required for most outdoor receptacles, bathroom receptacle circuits,
garage wall outlets, kitchen receptacles and all receptacles in crawl
spaces and unfinished basements.

You can get extension cords with GFCI.

For bands playing in an unknown venue, you don't know what you're
getting. Then again, it is not clear that the venue had anything to do with
this problem.

 

[Tunaman]

Bump for an old thread

Guitarists were getting their ass lit up like Christmas trees today at practice.

I have some investigating to do...

Heres some quick reading for folks

http://www.guitarnuts.com/technical/electrical/safety/index.php

Get one of these

http://www.tequipment.net/Ericson1099Series.html

 

[1958Bassman]

I don't care if it's a rig I've used 1000 times in a room I've worked 100 times. I don't care if Jesus Christ himself checked the electrical system first...

Grab the strings with your left hand, tap the back of your right hand on the mic. Every effing time.

You really should use a meter for this. If you can measure anything, the place has a problem. Better than zapping yourself. Using the opposite hand still sends the voltage/current through your body and that's risky, especially if the person doing this test has a pacemaker.

 

[throughthefire]

Originally Posted by Steve
I don't care if it's a rig I've used 1000 times in a room I've worked 100 times. I don't care if Jesus Christ himself checked the electrical system first...

Jesus Christ was a carpenter... I prefer an electrician every time...

 

[testing1two]

This is also a good reason to carry a foam windscreen for your mic. Unless you have a tremendous spitting disorder it will prevent lip-shock.

 

[georgestrings]

As Jimmy said earlier - MUCH earlier - this sort of situation illustrates one of the many benefits of going wireless...


- georgestrings

 

[Tunaman]

PA was plugged into an ungrounded outlet !

Guitarist extension cord had the ground plug broken off

=

Some damn good shocks (Probably well deserved however)

Now we have the whole damn band going through 1 grounded circuit, supposedly they are all 20A vs 15A so lets hope that bad boy holds up.... but at least we are grounded

 

[brotherdoc]

All electrical outlets will have the same ground potential if properly installed.

I was going to guess (which you already posted) that the ground prong was broke off on a cord. As somebody already mentioned, cut it off. Buy a cord cap and install it... cheap and easy. Black wire to brass colored screw, white wire to silver colored screw and green wire to green screw.

And yes, this is one of the many reasons to use a wireless system!